User Guide:

The Great Plains Environmental Flow Information Toolkit Hydrology Dashboard

Glossary

Alteration: anthropogenic disruption in the magnitude, duration, timing, frequency or rate-of-change of natural stream flows.
Acre-foot: an amount of water sufficient to cover one acre with one foot of water and equals 325,851 gallons.
Adjudication: a formal proceeding to determine the legal and quantitative rights to the use of surface  water.
Attainment frequency: the percent of time that a prescribed flow regime component is expected to be equaled or exceeded during select time periods (monthly, seasonally or annually) and natural or altered hydrologic conditions.
Average annual recharge: the amount of water that typically enters an aquifer on a yearly basis
Average Base flows: The base flow which was equaled or exceeded for 50%  of the flow record.
Average hydrologic condition:
Aquatic life use designation: a beneficial use descriptor used in the Texas Water Quality Standards in which a water body is rated by its ability to provide suitable habitat for survival and reproduction of desirable fish, shellfish, and other aquatic organisms.
Average discharge: the arithmetic mean volume of water which flows through a defined cross-section of a watercourse per unit of time.
Base flows: the range of “average” or “normal” flow conditions in the absence of significant precipitation or runoff events that provide a variety of suitable habitat conditions that support the natural biological community.
Basemap: a foundational mapping reference which provides a user with context for a map. Additional information can be added to a basemap by overlaying geographical feature layers on top of it.
Basin: the portion of land drained by a river and its tributaries. A river basin encompasses all of the land’s surface, which is dissected and drained by many streams and creeks that flow downhill into one another. Catalogued as HUC 6, there are 352 river basins within the U.S.
Beneficial use: the amount of water necessary when reasonable intelligence and diligence are used for a stated purpose; Texas Administrative Code (TAC) §297.43 recognizes the following uses as beneficial: (1) domestic and municipal, (2) industrial, (3) irrigation, (4) mining, (5) hydroelectric power, (6) navigation, (7) recreation, (8) stock raising, (9) public parks, (10) game preserves, (11) instream uses, water quality, aquatic and wildlife habitat, or freshwater inflows to bays and estuaries; and (12) other uses.
Component: a modular, self-contained portion of a software system that includes specific data and functionality exposed through one or more user interfaces. See Flow Regime Component to review the hydrologic definition.
Conservation: the careful preservation and planned management of a natural resource to prevent exploitation, destruction, or neglect.
Conservation storage: in a reservoir, the amount of water dedicated to water storage to meet water needs including municipal, domestic, agricultural, industrial, and recreational.
Consumptive use amount: the amount of water authorized by a water right to be completely used
Cubic foot per second: (cfs, cu ft/s, cusec and ft³/s) an Imperial unit / U.S. customary unit volumetric flow rate equivalent to a volume of 1 cubic foot flowing every second
Dashboard:  a type of graphical user interface which often provides at-a-glance views of key performance indicators relevant to a particular objective or business process
Dead storage: the volume in a reservoir below the lowest controllable level
Decision Support Tool: software developed to analyze data to compile comprehensive information in a simple format that can aid decision makers in efficiently making better informed decisions.
Deficit: the volumetric shortage of water necessary to meet the flow target.
Depletion: the progressive withdrawal of water from surface- or ground-water reservoirs at a rate greater than that of replenishment.
Discharge: the volume of water passing a point per unit time; see streamflow.
Dissolved oxygen (DO): the amount of oxygen gas dissolved in a given quantity of water at a given temperature and atmospheric pressure.
Diversion location: the geographical site at which water resources are transferred, channeled, stored, removed or consumed from its original water source
Diversion amount: the amount of water authorized to be removed from a surface water body; Texas water right permits authorize annual amounts in acre-feet.
Drainage area: the land area where precipitation is intercepted and flows into creeks, streams, rivers, lakes, and reservoirs identified by tracing a line along the highest elevation between two areas on a map.
Drainage basin: a part of the surface of the earth that is occupied by a drainage system, which consists of a surface stream or a body of impounded surface water together with all tributary surface streams and bodies of impounded surface water.
Drought: a period of deficient precipitation or runoff extending over an indefinite number of days.
Dry Base flows: the base flow value which was met 25% or less of the flow record, comprising periods of lower flows.
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EFIT: Environmental Flow Information Toolkit
Extent: the portion of area of a region show in a map. The limits of a map extent are defined in the coordinate system of the map
ESRI: Environmental Systems Research Institute
Feature: a cartographic point, line or polygon object with a spatial location in the real-world landscape that can be used in a GIS for storage, visualization and analysis
Feature Layer: a grouping of similar geographic features, such as buildings, parcels, cities, roads, and earthquake epicenters. Features can be points, lines, or polygons (areas). Feature layers are most appropriate for visualizing data on top of basemaps.
Filter—Reduces the number of features available to the target element or operational layer when it's rendering
Fish Barrier: anything that stops or impedes the movement of fish or other aquatic species in a stream.
Flood: a flow that exceeds the normal channel capacity and goes over the banks of a stream or river.
Flood-control storage: the storage of water in reservoirs above the conservation pool to abate flood damage.
Flow duration curve:  a plot of discharge vs. percent of time that a discharge was equaled or exceeded. The area under the flow duration curve (with arithmetic scales) gives the average daily flow, and the median daily flow is the 50% value. 
Flow Regime: the characteristic pattern of the duration, magnitude, timing and seasonal variability of streamflow.
Flow Regime Component: a single characteristic of the flow regime that is used to develop recommendations for naturalized stream flow. These characteristics can include magnitude, duration, frequency, timing, and rate of change.
Freshwater inflows: streamflows into bays and estuaries that maintain the natural salinity, nutrient, and sediment gradients needed to support  a sound ecological environment.
GNIS: the Geographic Names Information System developed by the U.S. Geological Survey to standardize geographic names and numerical identifiers for rivers and streams.
GP: Great Plains
Groundwater: water within the earth that supplies wells and springs; water in the zone of saturation where all openings in rocks and soil are filled, the upper surface of which forms the water table.
HEFR: Hydrology-Based Environmental Flow Regime; computer-based hydrologic model which consists of statistical calculations of hydrologic data for the purpose of populating a preliminary environmental flow regime matrix and identifying flow targets.
High Alteration: a significant trend in the difference between the frequency of attainment and the natural flow regime reflecting decreased flows below -25% attainment.
High flow pulses: the component of an instream flow regime that represents short-duration, in-channel, high flow events following storm events. They maintain important physical habitat features and longitudinal connectivity along the river channel.
HUC: (Hydrologic Unit Code) a sequence of numbers and a geographically significant name that identifies a hydrological feature.
HUC 6: the Hydrologic Unit Code at the river basin level. See Basin definition
HUC 8: the Hydrologic Unit Code at the sub-basin level. See Sub-basin definition
HUC 10: the Hydrologic Unit Code at the watershed level. See Watershed definition
HUC 12: the Hydrologic Unit Code at the sub-watershed level. See Sub-Watershed definition
Hydrograph: a graph where streamflow is plotted against time.
Hydrologic model: a computer model of a watershed used to evaluate how precipitation contributes to flow in streams.
Hydrologic unit: a geographic area representing part or all of a surface drainage basin or distinct hydrologic feature.
IHA: Indicators of Hydrologic Alteration; a software program developed by The Nature Conservancy that characterizes the impact of streamflow alteration on flow regimes.
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Impaired water body: a water body that cannot reasonably be expected to attain or maintain applicable water quality standards, and at least one designated use shows some degree of degradation.
Increased attainment: a significant trend in the difference between the frequency of attainment and the natural flow regime reflecting higher flows than modeled; greater than 10% attainment.
Instream flow recommendation: a target flow regime (i.e., the magnitude and timing of flow events) developed to maintain an ecologically sound environment in rivers and streams that can include subsistence and base flows, high flow pulses, and overbank flows.
Low flows: the streamflows that occur during a prolonged absence of rain. Probabilities of low flows can be assessed in a manner similar to the way that flood frequencies are expressed.
Moderate alteration: a change in the frequency of attainment and the natural flow regime reflecting decreased flows above -25% attainment but less than -10%.
Module: a software component or part of a program that contains one or more routines used to display analytical data
Naturalized conditions: an estimate of natural streamflow conditions obtained by attempting to remove effects of human activities from a set of measured conditions.
Negligible alteration: a change in the frequency of attainment and the natural flow regime reflecting decreased flows greater than -10% attainment but less than 10% suggesting minimal alteration to the natural flow regime.
Opportunity Areas: TPWD identified areas with the characteristics for developing successful flow restoration or protection strategies.
Overbank flows: the component of an instream flow regime that represents infrequent, high flow events that exceed the normal channel. These flows maintain riparian areas and provide lateral
connectivity between the river channel and active floodplain. They may also provide life-cycle cues for various species.
Period of record: the length of time that continuous, reliable measurements of streamflow or other weather elements are available at a particular location.
Period reliability: the probability that the full amount of water authorized in a water right permit will be available for diversion and use based on hydrologic records and water availability modeling.
Permit Type: categories of water rights as issued by the TCEQ, the water right permit designation in TCEQ databases is:
WRPERM = Water Right Permit
CF = Certified Filing
ADJ = Certificate of Adjudication
WRTP = Temporary Permit
WSC = Water Supply Contract.
Pre-Alteration: the period prior to human hydrologic impacts such as impoundment, diversion point or channel development, identified using the Indicators of Hydrologic Alteration (IHA) modeling.
Post-Alteration: the period affected by human hydrologic impacts such as impoundment, diversion point or channel development, identified using the Indicators of Hydrologic Alteration (IHA) modeling.
Priority Date: the date that a water right was granted or declared administratively complete, it indicates the seniority of one water right over another and, in Texas, is used to determine the order that water rights are honored during times of water shortage.
Range of Visibility
Reach: in general, a length of stream with relatively homogenous characteristics. In terms of the Texas Instream Flow Program, a subdivision of a segment that exhibits relatively homogeneous channel and floodplain conditions (hydrologic/ hydraulic, biological, geomorphic, and water quality).
Reachcode: the unique identification code for each stream reach defined by the USGS.
Return flow: the portion of diverted water that is not consumptively used and is returned to its original source or another body of water.
Segment: a water body or portion of a water body that is individually defined and classified in the Texas Surface Water Quality Standards and is intended to have relatively homogeneous chemical, physical, and hydrological characteristics.
Storage amount: the amount of water authorized for storage in a water right permit
Streamflow: the amount of water flowing in a river; see discharge.
Sub-basin: in general, a portion of a river basin cataloged as HUC 8
Subsistence flows: the minimum streamflow needed during critical drought periods to maintain tolerable water quality conditions and to provide minimal aquatic habitat for the survival of aquatic organisms.
Sub-Watershed: the smallest topographic scale for water boundaries. Large watersheds may contain hundreds or thousands of smaller subwatersheds that drain into the river or other water body. These subwatersheds are the perimeters of the catchment area of a stream tributary (See HUC 12)
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Target flows: the amount, rate and frequency of streamflows or freshwater inflows needed to support sound, natural ecological environments.
TPWD: Texas Parks and Wildlife Department
TCEQ:  Texas Commission for Environmental Quality
Time series: a set of data collected sequentially, usually at fixed intervals of time. For example, a hydrologic time series may provide average daily flow values at a location for a number of years of observation. A habitat time series could provide an estimate of corresponding average daily habitat conditions for the same time period.
Total Amount Permitted:
WAM: Water Availability Model: a numerical surface water accounting model used to determine the availability of surface water for water right permitting.
Total storage: the volume of a reservoir below the maximum controllable level including dead storage.
TWDB: Texas Water Development Board
USGS: United States Geological Survey
USGS streamflow gage: a location on a stream, canal, lake, or reservoir where systematic observations of the discharge of a stream is obtained. When used by USGS, the term “stream-gaging station” is only applicable to those gaging stations where a continuous record of discharge is obtained
Use type: the type of use of water in water right permitting, designated as any of the following:
Flood Control
Industrial
Agriculture
Livestock
Mining
Multiple uses  
Municipal
Other
Recreation
Recharge
Surface Water right:  a right acquired under the laws of Texas to impound, divert or use state water (Texas Water Code § 11.002(5)). A water right does not transfer ownership of the water from the state but instead grants the holder a non-possessory (usufructory) right of use while water ownership remains with the State of Texas. A water right permit is characterized by a permitted amount of use and/or storage, diversion rate, use type, priority date and potential special conditions including environmental provisions
Water right no.: Water Right Number; the unique identifier for water rights designated by the TCEQ
Water right type: See Permit type
Watershed: the area enclosed by a topographic divide, which drains to a specific location on a stream or river. Catalogued as HUC 10, these boundaries are typically between 40 to 250 K acres
Wet base flows: base flow conditions equaled or exceeded for 75% of the flow record, comprising periods of high flows.
Zoom: causes a target map element to zoom to a specified location
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